The conventional tree pruner is intended to remove dead or living parts from a tree so as to increase fruit or flower production or improve the tree form. As shown in FIG. 1, a tree pruner of the prior art is provided at the top end thereof with a bracing rod 1 having a fitting body 11 which is in turn provided with a fastening piece 12. The fastening piece 12 is provided at one end thereof with an arcuate portion 121 and is fastened pivotally at other end thereof with a pull rod 13. Located between the pull rod 13 and the fastening piece 12 is a tension spring 14. The fastening piece 12 is fastened pivotally with a cutting piece 15 which is fastened pivotally at other end thereof with the pull rod 13. The pull rod 13 and the fitting body 11 are provided respectively with a pulley 16, 17. A pull cord 18 runs through the pulleys 16, 17. As the pull cord 18 is pulled, the pull rod 13 and the cutting piece 15 are actuated.
In operation, the arcuate portion 121 of the fastening piece 12 and the cutting piece 15 are supported on a tree twig before the pull cord 18 is pulled to actuate the pull rod 13 to swivel so as to actuate the cutting piece 15 such that the tree twig is severed by the cutting piece 15 in conjunction with the arcuate portion 121. As the pull cord 18 is let go, the pull rod 13 and the cutting piece 15 are forced by the elastic force of the tension spring 14 to return to their original positions. The tree pruner is once again ready to work.
Such a tree pruner of the prior art as described above is defective in design in that the cutting piece 15 and the arcuate portion 121 are not able to sever a rough tree twig in one step, and that the user of the tree pruner must pull the pull cord 18 with a greater effort to actuate the cutting piece 15 and the arcuate portion 121. In other words, the tree pruner of the prior art does not work efficiently.